Vatroslav Lisinski Concert Hall, Zagreb Days of Oris is an international architectural festival organized by Oris House of Architecture, held since 2001. Every year it gathers more than 2000 participants – architects and professionals from related fields. So far, 367 top experts and speakers from all over the world have participated in the Festival. Join us for the 23rd edition of the Festival Days of Oris, to be held 3 – 4 November 2023 at the Concert Hall Vatroslav Lisinski in Zagreb, Croatia.